Web-roll driving apparatus for automatic splicing rollstand



W. F. HUCK Nov. 28, 1967 WEB-HOLL DRIVING APPARATUS FOR AUTOMATIC SPLICING ROLLSTAND 4 Sheets-Sheet l Filed June 18, 1965 W. F. HUCK Nov. 28, 1967 WEB-ROLL DRIVING APPARATUS FOR AUTOMATIC SPLICING ROLLSTAND 4 Sheets-Sheet 2 Filed June 18, 1965 ATTORNEY Nov. 28, 1967 w. F. HUCK 3,355,120

WEB-ROLL DRIVING APPARATUS FOR AUTOMATIC SPLICING ROLLSTAND Filed June 18, 1965 4 Sheets-Sheet 5.

INVENTOR WILLIAM F. HUCK AT TORN EY Nov. 28, 1967 w. F. HUCK 3,355,120v

WEB-ROLL DRIVING APPARATUS FOR AUTOMATIC SPLICING ROLLSTAND Filed June 18, 1965 l 4 Shee'cs-Snee 4 FIG.V 4.

fsf@ fase 54 /32 /46 /36 INVENTOR wlLLlAM F. HucK ATTORNEY United States Patent O 3,355,120 WEB-ROLL DRIVING APPARATUS FOR AUTOMATIC SPLICING ROLLSTAND William F. Huck, 81 Greenway Terrace, Forest Hills, N. 11375 Filed June 18, 1965, Ser. No. 464,926 17 Claims. (Cl. 242-5853) ABSTRACT OF THE DISCLOSURE In a rollstand for splicing a running web from an expiring roll rotated by a first drive belt to a new roll of larger diameter rotated by a second drive belt, and in which thereafter, in the course of movement of the new roll into driving engagement by the first belt, both belts simultaneously engage the new roll; the new roll is gradually accelerated, before splicing, by non-slip engagement therewith of a progressively increasing length of the second belt While correspondingly increasing the driving force transmitted to such belt, and there is provided a certain drive ratio between the belts at the moment of splicing and a different drive ratio therebetween during the simultaneous engagement of both belts with the new roll, whereby the roll contacting surfaces of both belts are driven at precisely the same speed at the times in question.

This invention relates generally to web handling devices for transferring a running web from one rotating roll to another at-a moment when the two rolls have substantially different diameters, for example, as in automatic splicing rollstands for uninterruptedly supplying a continuous web of paper, cloth, felt, metal foil, or the like, to high speed printing presses or other continuous web processing machines.

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edge to the expiring web are not fully capable of avoidv ing severe disturbances of the web tension or damage to the web, particularly in the outer layers of the new web roll. For example, if the main drive belts and the accelerating belts are4 driven at the same linear speed, measured at their pitch lines, that is, mid-way between the surfaces of the belts, the new web roll is driven at a peripheral speed greater than the speed of movement of the web being unwound from the expiring web roll and a sharp drop in web tension occurs immediately after splicing is effected. The foregoing disparity between the peripheral speeds of the new web roll and the expiring web roll, when driven by belts having exactly the same linear speeds at the pitch lines thereof, results from the fact that the new web roll has a far greater diameter than the expiring web roll. Thus, when the respective belts have substantial lengths thereof wrapped on the peripheral surfaces of the new web roll and the expiring web roll so as to have non-slip frictional contact therewith, different proportions of belt thickness to radius of curvature exist at the regions of contact of the accelerating belts with the large diameter new web roll and of the main drive belts with the small diameter expiring web roll. Assuming, by Way of example, that the accelerating belts and the main drive belts have the same thickness of 0.2 inch, and are driven at exactly the same linear speed, at their pitch lines, it can be shown that the peripheral speed of a new web roll having a diameter of 50 inches will be 4.5% greater than the peripheral speed of the expiring web roll having a diameter of 4 inches. Since the main unwinding or drive belts are of greater length than the accelerating belts, the main drive In existing web handling devices or rollstands for transferring a running web from one rotating roll to another, for exa-mple, as in the lautomatic splicing roll'- stand disclosed in U.S. Patent No. 3,103,320, issued Sept. 10, 1963, to William F. Huck, the expiring web roll, that is, the roll from which web is being supplied to a printing press or other web processing machine, is rotated by one or more main unwinding or drive belts frictionally engaging the surface of the expiring web roll and being moved at a speed which is controlled by the tension of the web itself so as to tend to maintain a constant value with the running speed of the web being unwound from the expiring web roll and thus permit splicing of the leading edge of the new web ro1l.to the trailing edge portion of the expiring web roll without interruption of the continuous supplying of web to the associated web processing machine. If the means controlling the speed of the accelerating belts are separate from the web tension responsive means controlling the speed of the main drive belts, it is difficult to match the speed of the new web roll to that of the expiring web, as only the latter speed is then automatically varied in re'- sponse to changes in the tension of the web itself. Accordingly, in U.S. Patent No. 3,103,320, it'has been propose to control the speeds of the main unwinding or drive belts and the accelerating belts by the same web tension responsive variable speed drive; before, during and after the splicing operation.

. However, it has been found that the existing arrangements for effecting controlled rotation of the new web roll before, during and after the splicing of its leading belts usually have a larger thickness, and such difference in belt thicknesses further increases the difference between the speeds at which the accelerating belts and the main drive belts drive the new web roll and the expiring web roll, respectively.

Although it has been proposed to drive the accelerating belts from the same web tension responsive, variable speed drive as the main unwinding or drive belts, but at a proportionately slower speed, measured at the respective pitch lines ofthe belts, so that the peripheral speed of thel new web roll, when driven by the accelerating belts, exactly corresponds to the speed of movement of the web unwound from the expiring web roll driven by the main unwinding belts at the moment of splicing or transfer of the running web from the expiring roll to the new roll, that proposal merelyl leads to a further problem. This'further problem arises after the leading edge of the new web roll has been spliced to the trailing edge portion of the expiring web roll, at which time, the new web roll is moved from the splicing position, where it is driven only by the accelerating belts, to the normal running position, where it is driven only by the -main unwinding or drive belts. In the course of such movement of the new web roll, both sets of belts simultaneously engage the new web roll. If the accelerating belts and the main unwinding or drive belts are driven at different speeds, measured at their pitch lines, during their simultaneous contact with the new web roll, the roll contacting surfaces of the belts are similarly moving at different speeds and severe disturbances of the web tension and possible damage or braking of the web may result.

Further, when continuously driven accelerating belts are brought into engagement with the new web roll at the splicingposition for accelerating the initially stationary new roll up to the speed of the expiring web, the sliding of the beltsrelative to the roll surface that occurs until the peripheral speed of the roll has become equal to the belt speed causes severe damage to the outside layers or turns of the web roll. Even if the machine operator 3 manually effects initial `acceleration of the new -roll prior to its engagement by the continuously driven accelerating belts, damage to the outside layers of the web roll still occurs by reason of the 4great disparity between the belt speed and the peripheral speed of the roll at the initial contact therebetween. Such an arrangement is, of course, further disadvantageous by reason of its undesirable dependence on manual labor.

One solution proposed for avoiding such damage of the outside layers of the new web roll during its acceleration has been the inclusion of an electromagnetic clutch of the variable energization type interposed in the drive for the accelerating belts to permit the latter to be brought into contact with the new web roll while the roll vand the accelerating belts are at rest, whereupon the electromagnetic clutch is progressively engaged and transmits a progressively increasing driving force to the accelerating belts for gradually accelerating ythe new web roll up to the desired speed. However, electromagnetic clutches suitable for the foregoing purpose, particularly those capable of having programmed rates 4of ener-gization so as to accommodate various roll sizes, weights and web surface characteristics, are relatively expensive and require repeated maintenance and frequent servicing and replacement.

Accordingly, it is a general object of this invention to provide an apparatus for transferring a running web from one rotating roll to another s-uch roll at a moment when the two rolls have substantially different diameters, for example, as in an automatic splicing rollstand, and wherein the rolls are driven in a manner to avoid the above mentioned disadvantages of apparatus previously provided lfor that purpose.

More specifically, it is `an object of this invention to provide an apparatus for ltransferring a running web from one rotating roll to another such roll at a moment when the two rolls have substantially different diameters, for example, as in an automatic splicing rollstand, wherein the peripheral speed of `the new web .roll is exactly matched to the speed of movement of .the web drawn from the expiring web roll at the moment of transfer, that is, at the instant when the leading edge of the new web roll is spliced to the trailing edge portion of the expiring web roll, and wherein, after such transfer or splicing is effected, movement-of the new web roll -to its normal running position, where it is ldriven only by the main unwind.- ing or drive belts, does not introduce vsevere disturbances in the tension of the running web which may be continuously supplied to an associated web processing machine.

In accordance with an aspect of this invention, the drive for the accelerating and main vdrive vbelts includes variable drive ratio means controlled to proportion the speed of the accelerating belts relative to the .speed ofthe main drive belts so as to -achieve a `peripheral speed of the large diameter new web roll equal to the lspeedof movement of the web being unwound from the small diameter expiring web roll immediately before and yduring `the splicing operation, and thereafter to change the drive ratio be,- tween the main drive belts land the accelerating belts so as to cause the belts to move at the same speed, at .their roll contacting surfaces, particularly during the `simultaneous engagement of the new web roll by both sets of belts occurring in the course of movement of the new web roll from the splicing position to .the normal' running position after the splicing or transfer operation.

It` is another object of this invention to provide a relatively inexpensive and maintenance-free drive for belts of an automatic splicing rollstand or the like by which a web roll is accelerated, such drive being at least equivalent, in its performance, to a drive including an electromagnetic clutch of the variable energization'type, in that it permits initial engagement of the accelerating belts with a web roll while the belts and roll are. at. rest land thereafter transmits a progressively increasing driving force to the accelera-ting belts as the area of contact thereof with the web roll is correspondingly increased for achieving the gradual acceleration of the web roll without slippage of the belts relative to the roll surface.

A further object is to provide means by which the accelerating belts of an automatic splicing rollstand are urged into contact with the surface of a new web roll by a force that is suciently large to prevent relative sliding of the belts on the roll surface during acceleration of the new web roll up to the desired peripheral speed, and thereafter to increase the force urging the accelerating belts against the surface of the new web roll, particularly during the splicingof the leading edge of the new web roll to the expiring web, thereby to maintain the non-slip contact of the accelerating belts with the new web roll and ensure accurate control of the speed thereof during the splicing operation.

Still another object is to provide an automatic splicing rollstand with an improved web tension control arrangement which is capable, at all times, of maintaining a desired tension in the web supplied to the associated printing press or other web processing machine.

The above, and other objects, features and advantages of the invention, will be apparent in the following detailed description of an illustrative embodiment thereof which is to be read in connection with the accompanying drawings, forming a part hereof, and wherein:

FIG. l is a schematic side elevational view of an automatic splicing rollstand incorporating the vfeatures of this invention, and being shown with the near side frame member removed for clarity;

FIG. 2 is a vdeveloped lplan view of the rollstand;

FIG. 3 is an enlarged fragmentary side elevational view showing the drive for the accelerating belts of the 4rollstand as viewed in the direction of the arrows 3-3 on FIG. 2;

FIG. 4 is an end elevational view of the rollstand; and

FIG. 5 is a diagrammatic view illustrating the relationship lbetween the speed of a belt at a roll contacting surface thereof 'and the radius of the roll.

Considerable simplification has been effected in the views of the drawings in order not to obscure the novel features characteristic of the invention with details of conventional parts well known to those skilled in the art. Also, where possible., conventional symbols have been used .for known components.

In the drawings, the invention is shown applied to an automatic splicing rollstand 10, but it is to `be understood that such rollstand .is merely illustrative, and that the invention may be applied to any vother apparatus, for example, 'a take-up or rewinding rollstand, in which a running web is transferred from one rotating roll 'to another such roll at a moment when the two rolls have substantially different diameters.

During normal running of 'the rollstand .10 the web W is 'unwound from a web supply roll 1a rotatably su-pported, at a normal running position R, between the 'ends of a pair of spider arms 1111 and 11b (FIG. 2) which 'are mounted at their centers on a rotatable horizontal shaft or spindle 12 journaled in bearings 13 (FIG. 4) lcarried by vertical side frame members vA an'd B. Spindle .12 may berotated by a 'gear 14 (FIG. 4) secured on an end of the spindle extending -beyond'side frame .member B and meshing with a pinion 15 mounted on the shaft extension of a motor 16 carried by a ybracket 17 extending from side frame memberB.

The web W unwound from web supply roll 1a passes upwardly around a'roller 18 journaled inside frame members A andv B and then travels to the left, as viewed on FIG. l, so as -to pass over a floating roller 19. Roller 19 forms part of a first variable speed drive mechanism 20 acting as a web tension control and 4which is generally of the type disclosed in the previously identified U.S. Patent No. 3,103,320, and also in U.S...Patent.No. 2,670,907, issued Mar. 2, 1954, to William F. Huck. Mechanism 20 functions to vary the speed at which Web W is unwound from roll 1a in response to changes in the tension of the web acting on roller 19. Such mechanism 20 includes a pair of arms 21a and 2lb having roller 19 rotatably supported between their outer ends, and being secured to a shaft 22 which is journaled in side frame members A and B. Roller 19 is urged upwardly into contact with web W by the pressure of lluid acting in a cylinder 23 which is pivotally supported, as at 24, by side frame member A, and which has its piston 25 pivotally connected, as at 26, to the adjacent arm 21a. Pressurized lluid is supplied to cylinder 23 through a conduit 27 extending from a main uid pressure supply conduit 28. The pressure of the fluid supplied to cylinder 23I may be adjusted by means of a pressure regulator 29, and is indicated by a pressure gauge 30, interposed in conduit 27.

Tension controlling variable speed drive mechanism 20 is driven from a main drive shaft 31 of the rollstand which is suitably connected to the drive (not shown) of the printing press or other web processing machine with which rollstand is associated. Main drive shaft 31 is connected, through bevel ygears 32 and 33, with a crossshaft 34 journaled in side frame members A and B (FIG. 2). An end of cross shaft 34 projecting beyond side frame member'B carries a V-belt pulley 35 which engages and drives a V belt 36 running around a variable diameter pulley 37. Variable diameter pulley 37 may be of the type disclosed in U.S. Patent No. 2,812,666, issued Nov. 12, 1957, to William F. Huck, and is secured on an end of a pulley shaft 38 which is journaled in side frame members A and B so as to be disposed above the web roll 1a in the normal running condition of the rollstand. The two runs of V-belt 36 between pulleys 35 and 37 pass under take-up pulleys 39 and 40 (FIG. 1). Pulley 39 is rotatably mounted on the outer end of an arm 41 which is secured to an end of shaft 22. Pulley 40 is rotatably mounted on the outer end of an arm 42 which is pivotally mounted on a stub shaft 43 carried by the adjacent side frame member B. Arms 41 and 42 are connected by a turnbuckle link 44 which is adjustable to vary its effective length so that pulleys 39 and `4i) can be thereby displaced toward and away from each other for initially adjusting the drive ratio between shafts 34 and 38 of tension control mechanism 20.

Shaft 38 has at least one drive pulley 45 thereon, and each drive pulley 45 is in driving engagement with a main unwinding or drive belt 46. The main unwinding or drive belt 46 travels downwardly toward the left, as viewed on FIG. l, from its drive pulley 45 and passes successively around idler pulleys 47 and 48, a take-up pulley 49, and idler pulleys 50 and 51.- Idler pulley 51 is disposed below drive pulley 45 so that the run of main unwinding or drive belt 46 moving upwardly from idler pulley 51 to drive pulley 45 is frictionally engageable with the surface of a web roll 1a when in the normal running position R, and also when the roll is in the expiring Iposition E indicated in full lines on FIG. 1. The several idler pulleys 47, 48, 50 and 51 are rotatable on shafts suitably journaled in side frame members A and B, and take-up pulley 49 is rotatable on a shaft 52 having its ends journaled in bearing blocks (not shown) which are vertically movable in guides 53 carried by side frame members A and B. Take up pulley 49 is urged upwardly, thereby to tension unwinding or drive belt 46, by the pressure of iluid acting in vertical cylinders 54 having their upwardly extending (piston rods S5 connected to the bearing blocks which support shaft 52. Fluid under pressure is supplied to each cylinder 54 from main supply conduit 28 by way of a conduit 56 having a pressure regulator 57 and pressure gauge 58 interposed therein for respectively adjusting the fluid pressure acting in each cylinder 54 and indicating such pressure.

The rollstand 10, to the extent described above, is generally similar to that disclosed in U.S. Patent No. 3,103,320, and operates in substantially the same way so as to maintain a substantially constant tension in the web being unwound from the web roll 1a at the normal running position R. More specifically, it will be seen that fluid under pressure acting -in cylinder 23 urges floating roller 19 upwardly and in a clockwise direction about shaft 22, and such upward force on roller 19 resulting from the pressure of iuid in cylinder 23 is in addition to the upward force exerted by belt 36 on pulleys 39 and 40. The foregoing forces urging floating roller 19 to move upwardly are balanced, when the web tension is` at a desired value, by the downward force exerted on oating roller 19 by the run of the web extending downwardly from the floating roller to an idler roller 59 positioned therebelow. An increase in the tension of the web W above the desired value, which is determined by the adjustment of the lluid pressure in cylinder 23, moves roller 19 lin the downward direction and causes corresponding counter-clockwise turning of shaft 22 so that pulleys 39 and 40 are moved downwardly against the corresponding runs of belt 36. Thus, the eifective length of the V-belt 36 is reduced, and

` this in turn reduces the elective engagement diameter of belt 36 on variable speed pulley 37. Since belt 36 is traveling at a constant linear speed in proportion to the speed at which the web is propelled by the printing press or other web processing machine, such reduction in the effective diameter of pulley 37 increases its rotational speed and hence increases the speed of movement of main unwinding or drive belt 46 and of the web being unwound from web roll 1a. The .feeding of the web W at a faster rate effectively reduces the tension of the Web acting on roller 19 and thus compensates for any increase of the web tension above the value originally set.

Conversely, when the tension in web W acting on floating roller 19 decreases below the value desired, floating roller 19 is moved upwardly to effect similar upward movement of pulleys 39 and 40, thereby increasing the effective length of V-belt 36 and also increasing the effective diameter of variable speed pulley 37. Thus, the 1'o tational speed of pulley 37 isreduced to decrease the speed of movement of main unvvinding or drive belt 46 and of the web being unwound from web roll 1a. The resulting reduction in speed of the web W increases the web tension acting on roller 19 and thus restores the web tension to the value originally set.

Although web tension control mechanism 20 is generally effective to maintain the desired value of tension' in a web fed directly therefrom into the associated printing press or other web processing machine during normal running of the rollstand, it has been found that the above described arrangement cannot always adequately compensate for the web tension variations that occur during rotation of the roll holding spider arms 11a and 11b and during automatic splicing, at which time the tensioned web is suddenly severed from an expiring roll of relatively low mass and connected to a large new roll of relatively great mass. Such web tension variations are particularly apparent as the operating speed of the associated web processing machine is increased and, if not compensated for, can cause misregister in subsequent printing or web processing operations or Web breaks and, in either case, result in uneconomical waste.

Accordingly, rollstand 10 embodying the present invention preferably has an additional or second web tension control mechanism 60 acting on the web between web tension control mechanism 20 and the associated web processing machine so as to maintain a desired tension in the web being fed to the web processing machine independently of the tension control exerted by varying of the speed of unwinding of the web from roll 1a.

As shown, web tension control mechanism 60 is generally of the type disclosed in U.S. Patent No. 3,083,887, issued Apr. 2, 1963, to William F. Huck and includes a drive roller 61 mounted on a shaft 62 journaled in side frame members A and B, and around which web W runs after passing under idlerl roller 59. 'I'he web is pressed into non-slip engagement with drive roller 61 by means of a .nip roller 63 rotatably mounted between the outer ends of arms 64 extending from a shaft 65 journaled in side frame members A and B. An arm 66 is also secured to shaft 65 and is pivotally connected, at its free end, to a piston rod 67 extending from a cylinder 68 which is pivotally mounted at 69 on the adjacent side frame member. Fluid under pressure is suitably supplied to cylinder 68 so as to act within the latter against the piston of rod 67 in the direction for urging the nip roller 63 toward web drive roller 62 with the web therebetween.

After passing between drive roller 62 and nip roller 63, the-web travels under the latter and then over a floating roller '7 0. From floating roller 70, the web W travels downwardly to an idler roller 71 positioned therebelow and then around successive idler rollers 72 and 73 which lead the web into the associated printing press or other web processing machine. Floating roller 70 is rotatably mounted between the outer ends of a pair of arms 74a and 74b which extend from a shaft 75 journaled in side frame members A and B. Arm 74a is pivotally connected at 76 to a piston 77 slidable in a cylinder 78 which is pivotally supported, at 79, by the adjacent side frame member A. Fluid under pressure Vis supplied to cylinder 78 from the main supply line 28 by way of a conduit 80 having a pressure regulator 81 and pressure gauge 82 interposed therein for respectively adjusting and indicating the pressure of the fluid acting in cylinder 78 to urge floating roller 70 upwardly against the Web.

The web tension control mechanism 60 further includes a V-belt pulley 83 which is secured on cross shaft 34 and drives a V-belt 84 running around a variable diameter pulley 85 secured on the shaft 62 of web drive roller 61. The variable diameter pulley 85 may be of the same type as pulley 37 so thata change in the effective length of V-belt 84 changes the effective engagement diameter of the belt on pulley 85 and thereby changes the drive ratio between shafts 34 and 62. In order to vary the effective length of belt 84, web tension control mechanism 60 further includes take-up pulleys 86 and 87 engageable from below with the runs of belt 84 extending between pulleys 83 and 85 and being respectively rotatably mounted on an arm 88 secured on shaft 75 and on an arm 39 which is pivoted on a stub shaft 90 extending from the adjacent side frame member B. An adjustable turnbuckle link 91 effectively connects the arms supporting pulleys 86 and 87 to cause joint movement thereof and also to permit the adjustment of such pulleys toward and away from -each other for initially adjusting the effective length of belt 84 and thereby initially adjusting the drive ratio between shafts 34 and 62.

The operation of web tension control mechanism 60 is as follows:

The force of the fluid pressure acting in cylinder 78 and the force of belt 84 on pulleys k86 and 87 urge oating roller 70 upwardly and are balanced by the desired value of tension in the web runs between nip roller 63 and floating roller 70 and between the latter and idler roller 71. If the web tension acting on roller '70 increases above the desired value, roller 70 is moved downwardly and the corresponding upward movements of pulleys 86 and 87 reduce the keffective length Aof belt 84 and thereby reduce the effective diameter of pulley 85 so that the rotational speed of the latter and of the web driving roller 61 are increased. The resulting increase in the speed of the web serves to reduce the tension in the web acting on roller 70. Conversely, if the tension in the web acting on roller 70 is reduced below thendesired value, floating roller 70 moves upwardly to effect corresponding downward movement of pulleys 86 and 87, thereby to increase the effective length ofbelt 84 and the effective diameter of pulley S5. The increase in the effective .diameter of pulley 85 reduces the rotational speed thereof and thereby reduces .the speed of movement of the web by drive roller 61 so thatthe tension in the web acting on floating roller 70 is increased to the desired value.

Under normal operating circumstances, floating rollers 19 and 70 of the two web tension control mechanisms move relatively small distances from the positions illustrated on FIG. l in order to effect all of the necessary corrections or variations in web speed for maintaining the desired web tension. However, in order to limit upward movement of arms 21a and 2lb and of arms 74a and 74h in the event of a break of the web or any other abnormal reduction in web tension, stationary rods 92 and 93 extend laterally between side frame members A and B above arms 21a and 2lb and arms 74a and 7411, respectively, and act as stops or abutments therefor.

Although both web `tension control mechanisms 20 and are driven from the same cross shaft 34, it will be noted that such mechanisms react individually to the tensions in the web at the respective floating rollers 19 and 70. The mechanism 20 reacts to variations in web tension from the desired value by effecting corresponding changes in the speed at which the web is unwound from the web roll engaged by thev main unwinding or drive belt 46, whereas mechanism 60 reacts to variations of web tension from the desired value by changing the speed at which the web is propelled by the web driving roller 61. To the extent that mechanism 20 may be unable to compensate for web tension variations occurring during rotation of the roll-holding spider arms 11a and 11b or during the splicing operation, additional, adequate compensation is provided by the second web tension register control mechanism 60 so that the web supplied continuously to the printing press or other web processing machine has its tension uniformly maintained at the desired value.

Although the explanations given above as to the operation of unwinding or drive belt 46 and driving roller 61 have referred to the same as driving the web, it will be understood that belt 46 and roller 61 do not, in fact, exert driving forces, but rather retard the web so as to permit the latter to move only rapidly enough to establish the desired tension which is correctly balanced by the variable speed drives and the associated yieldable balancing forces, that is, the forces exerted by the fluid pressure containing cylinders 23 and 78 which obviously may be replaced by adjustable springs.

When a web roll 1a held between ends of spider arms 11a and 11b is disposed at the normal running position R and the web is being unwound therefrom, as described above, the opposite ends of the spider arms are disposed at a loading position L so as to receive a new web roll. After a substantial proportion of the web on roll 1a at the normal running position R has been unwound therefrom, motor 16 is suitably energized to effect rotation of spider arms 11a and 11b to the position shown in full lines on FIG. l. After such rotational movement of spider arms 11a and 11b, web roll 1a is disposed at the expiring roll position E, and new web roll 1b is disposed at a splicing position S. When in the splicing position S, the peripheral surface of new roll 1b is spaced only a relatively small distance from the run of web W moving upwardly from web roll 1a at the expiring position E to idler roller 18. Upon reaching the splicing position S, new roll 1b is rotationally accelerated by means of a device 94. The accelerating device 94 includes at least one accelerating belt 95 which engages and is driven by a drive pulley 96 on a shaft 97 having its end portions rotatably mounted in sleeve housings 98a and 98!) extending inwardly from side frame members A and B. Arms 99a and 99h constituting a frame of accelerating device 94 are rockably mounted on sleeve housings 98a and 98b, respectively, to permit movement of the accelerating device 4.from its operative position shown in full lines .on FIG. l to its inoperative or raised position shown in broken lines on FIG. 1. A shaft 100 is rotatably mounted in the outer or free ends of arms 99a and 9912r and carries an idler roller 101 around which the accelerating belt 95 passes so that a substantial length of the lower run of belt 95 between drive pulley 96 and idler pulley 101 can be moved against and frictionally contact the periphery of new web roll 1b at splicing position S when the accelerating device is in its operative position. The return run of belt 95 passes over an idler pulley 102 rotatable on a shaft 103 having its ends journaled in arms 99a and 99h, and then over a tensioning pulley 104 which is supported and actuated in a manner hereinafter described in detail.

Shaft 97, and hence drive pulley 96, is driven from shaft 38 of web tension control mechanism 20 by means of a drive assembly 105 (FIGS. 2 and 3). Since the rotational speed of shaft 38 is varied by the variable speed drive constituted yby pulley 35, belt 36 and pulley 37 in response to variations of the web tension acting on floating roller 19 from a desired value of such tension, it will be apparent that any change in the speed of movement of main unwinding or drive belt 46 by its drive pulley 45 on shaft 38 results in a similar change in the speed of movement of -accelerating belt 95 by its drive pulley 96 on shaft 97. However, even if belts 46 and 95 were driven at the same linear speeds, measured at their pitch lines, new web roll 1b would be driven at a peripheral speed greater than the speed of movement of the 'web being unwound from expiring web roll 1a. Such disparity between the peripheral speeds of new web roll 1b and expiring web roll 1a, when driven by belts having exactly the same linear speeds at the pitch lines thereof, results from the fact that roll 1b has a far greater diameter than roll 1a and thus, at the regions where belts 46 and 95 are wrapped on substantial circumferential portions of rolls 1a and 1b so as to be in non-slip frictional contact therewith, belts 46 and 95 have different proportions of belt thickness to radius of curvature. As a typical example, if belts 46 and 95 have a thickness of 0.2 inch and are driven at exactly the same linear speeds, measured at their pitch lines, and if new web roll 1b has a diameter of 50 inches and expiring web roll 1a has a diameter of 4 inches, the peripheral speed of the new web roll 1b will be 4.5% greater than the peripheral speed of expiring web roll 1a. yIn the foregoing example, the thicknesses of belts 46 and 95 have been assumed to be equal, but in most cases main unwinding or drive belt 46 is made with a greater thickness than accelerating belt 95 by reason of the substantially greater length of belt 46, and such diierence between the thicknesses of belts 46 and 95 further increases the difference between the speeds at which the rolls 1a and 1b are driven by the respective belts.

An appreciation of the above may be gaine-d from FIG. 5, wherein a single belt 1 is shown, merely for thel purpose of this explanation, in driving engagement with a small diameter roll 2 and with a large diameter roll 3. Since only a single belt is involved, it is apparent that the speed Vp of the belt at its pitch line p is thev same throughout the length of the belt. However, at the length x-x of the belt in driving engagementwith roll 2, a point at the roll -contacting surface of the belt travels a shorter distance than a corresponding point at the pitch line and thus the speed V2 at the surface of belt 1 in contact with roll 2 is less than the speed Vp. Similarly, at the length y--y of belt 1 in driving engagement with roll 3, a point at the roll contacting surface of the belt travels a shorter distance than a corresponding point at the pitch line so that the speed V3 at the surface of belt 1 in contact with roll 3 is also less than the speed V15. The extent to which each of V2 and V3 is less than Vp is proportional to the thickness t of the belt and inversely proportional to the radius of the respective roll. Since the radius of roll 2 is less than the radius of roll 3, Vp-Vz is greater than Vp-V3 or V3 is greater than Although it is a simple matter to proportion the drive between shaft 38 of web tension control mechanism 20 and shaft 97 of accelerating device 94 so that accelerating belt is always driven at a speed, measured at its pitch line, that is sufficiently slower than t-he speed of movement of belt 46, also at its pitch line', to provide a peripheral speed of new web roll 1b, when driven by belt 95, that is exactly equal to the speed of movement of the web W being unwound from expiring web roll 1a driven by belt 46, that does not fully solve the problem. After the leading edge of the web of new roll 1b is spliced to the trailing edge portion of the web from expiring roll 1a and the web from roll 1a is severed in back of the location of the splice, for example, as described in detail in the previously fully identified U.S. Patent No. 3,103,320, motor 16 is again operated to turn roll-holding spider arms 11a and 11b and thereby move new web roll 1b from splicing position S, where it is driven only by accelerating belt 45, to normal running position R, where the new web roll is driven only by main unwinding or drive belt 46. In the course of such movement of the new web roll from splicing position S to normal running position R, the new web roll passes through intermediate positions where it is simultaneously engaged and driven by both belts 46 and 95. It is obvious that, when both belts 46 and 95 simultaneously engage the surface of new web roll 1b, and hence have the same curvatures at the lengths in contact with that roll, the speeds at which the two belts are driven must match in order to avoid severe disturbance of the tension of the web being unwound from the new web roll for feeding to the associated printing press or other web processing machine.

In accordance with this invention, drive between shaft 38 of web tension control mechanism 20 and shaft 97 of accelerating device 94 is constructed and arranged to provide a variable drive ratio between pulley 45 driving belt 46 and pulley 96 driving belt 95. Drive 105 provides :a certain drive ratio by which the surface or peripheral speed of new web roll 1b at splicing position S is made to exactly match the speed of the web being unwound from expiring web roll 1a both before and during the actual splicing operation. After the splicing operation, drive 105 provides a different -drive ratio between belts 95 and 46 so as to exactly match the speeds of these belts at the surfaces thereof which simultaneously contact and drive the new web roll in the course of its movement from splicing position S to normal running position R.

In lorder to perform the above functions, drive 10-5 may conveniently include a fixed dia-meter V-belt pulley 106 fixed on the end of shaft 38 remote from pulley 37 and driving a V-belt 107 which engages and runs around a variable diameter V-belt pulley 108 secured on an end of shaft 97 projecting beyond sleeve housing 98a (FIGS. 2 and 3). Variable diameter pulley 108 may be of the type disclosed in the previously fully identified U.S. Patent No. 2,812,666. V-belt 107 is further engaged by a take-up pulley 109 rotatably mounted at one end of a lever 110 which is rockable about a pivot 111 disposed intermediate the ends of lever and carried by the adjacent side frame member A. Connected to the end of lever 110 remote from pulley 109 is a piston rod 112 extending from a piston which is slidable in a cylinder 113 mounted, as at 114, Ion the adjacent side frame member A. Also-connected to lever 110, at a location between its pivot 111 and the piston rod 112, is a link 115 connected at 116 to the upper end of a threaded -rod 117 slidable axially in the bore of a hollow screw 118. Screw 118 extends adjustably through an internally threaded bracket 119 projecting from the adjacent side frame member A. The adjustment of hollow screw 118 relative to -bracket 119 is maintained by a lock nut 120 threaded on screw 118. The lower end portion lof threaded rod 117 receives stop nuts 121 which are engageable with the lower end of hollow screw 118 to adjustably limit upward movement of threaded rod 117 and hence rocking of lever 110 in the 11 counterclockwise direction, as viewed on FIG. 3, whereas downward movement of rod 117, and hence clockwise rocking of lever 110, is adjustably limited by engagement of the lower end of link 115 with the head at the upper end of hollow screw 118. The piston rod 122 of a dashpot cylinder 123 supported by the adjacent side trame member A is also pivotally connected to lever 110. The opposite ends of the -dashpot cylinder are connected by a conduit 124 having an adjustable orifice or needle valve 125 interposed therein to regulate the rate of flow of uid between the lopposite end portions of the dashpot cylinder, and hence to regulate the rate of angular movement of lever 110 between its opposite extreme positions determined by the adjustment of screw 118 and nuts 121.

The opposite ends of cylinder 113 alternately receive uid under pressure, for example compressed air, or are vented to atmosphere by way of conduits 126 and 127 extending from a solenoid controlled valve 128 having an exhaust port 129 or vent to the atmosphere and a connection to a conduit 130 extending from main liuid pressure supply conduit 28 shown on FIG. 1. A pressure regulator 131 is interposed in conduit 130 so as to determine the pressure of the fluid acting alternately in the opposite end portions of cylinder 113.

The energization of solenoid valve 128 is suitably controlled in synchronism with the controls for the other components of the rollstand, for example, as generally disclosed in the previously fully identified U.S. Patent No. 3,106,320, so that during `movement of a new web roll from loading position L to splicing position S, and so long as the new web roll remains at the splicing position, valve 128 supplies fluid under pressure Ithrough conduit 127 to the lower portion of cylinder 113 and vents or exhausts fluid from the cylinder 113 by way of conduit 126, thereby causing lever 110 to be rocked to the position shown on FIG. 3. Nuts 121 on threaded rod 117 are adjusted so that, with lever 110 in the position shown on FIG. 3, the action of pulley 109 on belt 107 will result in an effective diameter of engagement of variable diameter pulley 108 with the belt providing a drive ratio between shafts 38 and 97 that causes accelerating belt 95 to drive the large diameter new web roll 1b at exactly the same peripheral speed as the speed of the web being unwound from the small diameter expiring web roll 1a by main drive belt 46. The foregoing assures that slack will not be introduced into the web at the moment when the leading edge of the new web roll is spliced or joined to the web being unwound from the expiring web roll.

Simultaneously with the commencement of further turning of spider arms 11a and 11b f-or moving the new web roll to normal running position R after the splicing operation, solenoid valve 128 is energized or actuated so that fluid under pressure is then supplied to the upper end portion of cylinder 113 through conduit 126 while the lower end portion of cylinder 113 is exhausted or vented to atmosphere by way of the conduit 127. The resulting clockwise rocking of lever 110 raises take-up pulley 109 and thereby reduces the effective length of belt 107 by increasing the tension therein. As a result of the reduced effective length of belt 107, the effective diameter of engage-ment thereof with pulley 108 is reduced, thereby increasing the speed of shaft 97 and the drive pulley 96 thereon for correspondingly increasing the speed of accelerating belt 95 relative -to the speed of belt 46. Hollow screw 118, which determines or limits clockwise rocking of lever 110, is adjusted relative to bracket 119 so that, when the speed of accelerating belt 95 is increased, as described above, the speed at the surface of belt 95 in contact with the surface of new web roll 1b exactly matches the speed of movement at the active surface of main drive belt 46 when in contact with the new web roll.

The adjustable metering orifice or needle valve 125 `which regulates the flow between the opposite ends of dashpot cylinder 123 is adjusted so that a substantial period, for example, to l0 seconds, is required for movement of lever 110 from the position shown on FIG. v3 to the position determined by contact of link 115 with the head of screw 118. Such relatively slow rocking of lever 110 ensures that, after the splicing operation, the, drive ratio provided by drive 105 will be gradually changed from the ratio required for matching the surface speeds of the expiring web roll 1a and the new web roll 1b when driven individually by the belts 46 and 95, to the drive ratio providing the same speeds at the active surfaces of `both belts 46 and 95 when such belts simultaneously engage the new web roll 1b during the transitional stage between the drive of roll `1b exclusively by belt to the drive of that web roll exclusively by belt 46. The foregoing assures uniform web tension regulation during the transitional period, and that changes in the position of the floating roller 19 for detecting and controiling the unwinding web tension will take place gradually and occur before the main drive belt 46 has completely taken over the driving or unwinding of the new web roll. The above indicated period of time rfor angular displacement of lever 110 is well within the respouse time of web tension control mechanism 20 so that abrupt or severe disturbance of the desired web tension conditions in the unwinding web are avoided during the splicing operation and during the movements of the successive web rolls between the indicated positions.

Although the illustrated embodiment of the invention shows main drive belt 41 being driven directly from shaft 3S of web tension control mechanism 20 and variable speed drive interposed between that shaft 38 and shaft 97 of accelerating device 94, it will be under'- stood that, in an alternative embodiment of this invention, drive pulley 96 of accelerating device 94 may be mounted directly on shaft 38 of web tension control mechanism 20 and, in that case, drive pulley 45 of main drive belt 46 is mounted on a shaft other than shaft 38 and which is coupled to the latter by way of the described variable speed drive 105.

lt is further apparent that, although a single main drive belt 46 and a single accelerating belt 95 are shown on the drawings, two or more laterally spaced main drive belts and two or more laterally spaced accelerating belts may be provided.

It will be noted that, when new web roll 1b is moved from loading position L to splicing position S and intially engaged by accelerating belt 95, web roll 1b is rotationally at rest or standstill. If accelerating belt 95 is being moved by a large driving force at the moment of its initial contact with the surface of `stationary new web roll 1b, the resulting slipping of belt 95 relative to the surface of roll 1b will frictionally tear or damage the outer layers of the new web roll. In accordance with this invention, accelerating device 94 is arranged so that, when such device is in its inoperative position shown in vbroken lines on FIG. l, belt 95 is slack on pulley l96 and is held at rest. Further, as device 94 is moved to its operative position indicated in full lines, and thus has the run of belt 95 extending from drive pulley 96 to idler pulley 101 urged into frictional contact with the surface of roll 1b at Ya progressively increasing length of said run of the belt, the initial contact with roll 1b serves to take-up slack in belt 95 and cause commencement of movement of the belt in contact with the roll surface and, thereafter, the extent or" the wrap of belt 95 on driving pulley 96, and hence the driving force that can be transmitted to belt 95, is progressively increased. Thus, initial engagement of accelerating belt 95 with the surface ofthe sta,- tionary new web roll 1b is achieved with the belt at rest and, after that initial engagement, only a relatively small driving force is transmitted from drive pulley 96 to belt 95 and slippage occurs therebetween rather than Ibetween belt '95 and the surface of roll 1b. As roll 1b is thus slowly accelerated from standstill ,and is engaged by a progressively increasing length of belt 95, the driving force transmitted from pulley 96 to belt 95 is progres- 13' sively increased, with the contact force and area of contact of the accelerating belt against the surface of roll 1b always suiciently large to ensure the transmission of the increasing driving force from belt 95 to the surface of the web roll without slippage therebetween.

In the illustrated embodiment of this invention, the above described advantageous operating characteristics of accelerating device 94 are achieved by mounting takeup pulley 104 thereof on a shaft 132 having its ends journaled in arms 133a and 133b (FIGS. l and 2) which are pivotally mounted on a rod 134 fixed between extensions 135:1 and 13512 of arms `99a and 99b, respectively. The ends `of shaft 132 are further connected to piston rods 136 extending from cylinders 137 which are pivotally connected, as at 138, to mounting brackets 139 secured to the inner faces of arms 99a and 99b. Fluid under pressure is supplied to each cylinder 137 through a conduit 140 extending from main iluid pressure supply conduit 2.8 and having a pressure regulator 141 interposed therein so that take-up pulley 104 is yieldably urged upwardly and toward the left, as viewed on FIG. 1, along an arcuate path concentric with rod 134. Adjustably secured on rod 134 are a pair of arms 14261 and 14211 which support a stop rod 143 extending therebetween and serving to limit the `movement of take-up pulley 104 under the influence of liuid under pressure acting in cylinders 137.

In order to effect the movement of accelerating device 94 between its inoperative'and operative positions, extentions 135a and135b of arms 99a and 99b are pivotally connected, as at 144 (FIG. l), to forked ends of piston -rods 145 extending from cylinders 146 which are pivotally supported, as at 146a, by adjacent side frame members A and B. In orderto control the movements of accelerating device 94 by uidunder pressure supplied to cylinders 146, conduits 147 and 148 extend from the opposite ends f each cylinder 146 to one side of a solenoid controlled valve 149, and ow control or metering valves 150 and 151 are interposed in conduits 147 and 148, respectively, forfcontrolling the rate of fluid iiow therethrough' into the related ends of Acylinder 146. Connected to valve 149 are a conduit 152 extending from main fluid pressure supply line 28 and having a pressure regulator 153 interposed therein which is adjusted to establish a relatively high pressure, for example, 50 p.s.i., and which is capable of bleeding excess pressure fluid from conduit 152. A conduit 154 extending from a second solenoid controlled valve 155 is also connected to valve 149. Valve 155 is connected to the main ,supply conduit 28 through a conduit 156 having a pressure regulator '157 and pressure gauge 158 interposed therein, and valve 155 has a vent or discharge port 159.

Pressure regulator 157 is adjusted to establish a relatively low pressure, for example, 30 p.s.i., in the conduit 156. The above described arrangement for controlling the movements of accelerating device 94 operates as follows:

Initially, solenoid valves 149 and 155 are deenergized. When valve 149 is deenergized, it connects conduit 148 with conduit 152and conduit 147 with conduit 154, and when valve 155y is deenergized, it connects conduit 154 with `the -vent orfdischarge port 159. Thus, at the start of an operating sequence or cycle, fluid under relatively high pressure-is suppliedfrom conduit 152 to the righthand: end of each cylinder 146, as viewed 'on FIG. 1, and the left-hand end of each cylinder 146 is vented. The high ilui'dpressure acting in theright-hand end of each cylinder 146 produces a force sufficient to overcome the weight of accelerating device 94 and to raise the latter to its inoperative position; When device 94 is in its raised or inoperative position, the run ,of belt 95 between drive pulley 96 and idler pulley 101 can f'ollow a relatively straight or short path, and a major portion of the resulting slack in belt 95 is taken up by the movement of pulley 104 toward the left and'upwardly under the influence of fluid pressure in cylinders 137, thereby to decrease the wrap of belt 95 on drive pulley 96. Arms'142a and 142b are angularly adjusted so that stop `rod 143 carried thereby is engaged i of belt 95 on drive pulley 96 is to progressively increase by the belt wrapped on take-up pulley 104 before arms 99a and 99b attain their fully raised positions, whereby some slack is present in belt when device 94 is in its inoperative position. The engagement of stop rod 143 with belt 95 on take-up pulley 104 stops the movement of belt 95 and free slipping of the continuously rotated drive pulley 96 relative to belt 95 is made possible by the relatively small wrap of the belt on the drive pulley and also by the slack present in belt 95.

After spider arms 11a and 11b have been turned to move new web roll 1b from loading position L to splicing position S, solenoid valve is suitably energized and thereby permits uid under pressure from conduit 28 to enter the left-hand end of each cylinder 146 by way of conduit 156, energized valve 155, conduit 154, deenergized valve 149 and conduit 147. Although the pressure regulator 157 in conduit 156 is set for a pressure lower than that established in conduit 152 by regulator 153, the force resulting from the relatively low pressure acting to the left of the piston in each cylinder 146 and the weight of the components of accelerating device 94 pivotally suspended from shaft 97 more than overcome the counterforce resulting from the relatively high pressure acting to the right of the piston in each cylinder 146, and arms 99a and 99b are, accordingly, moved downwardly from their raised position. The flow control valve 151 in conduit 148 is adjusted to ensure that the downward movement of arms 99a occurs at a slow rate to provide a similarly slow progressive increase in the length of belt 95 in contact with the new web roll.

It will be noted that, when accelerating device 94 is in its lraised or inoperative'position shown in broken lines on FIG. 1, the lower or active run of belt 95 extending from drive pulley 96 to idler pulley 101 is spaced only a small distance from the surface of new roll 1b in the splicing position S. Thus, at the commencement of the downward movement of accelerating device 94 from its raised or inoperative position, the initial contact of belt 95 with roll 1b is effected while belt 95 is still slack and is'locked against movement by its engagement between take-up pulley 104 and stop rod 143. Following such initial contact of belt 95 with the surface of web roll 1b, further downward movement of arms 99a and 99b causes the initial slack in belt 95 to be taken up by pulley 104 and the movement of belt 95 on pulley 104 away from stop rod 143-so that belt 95 is then free to be driven by its frictional engagement with drive pulley 96. However, when belt 95 is first freed from engagement with stop rod 143, there is only a relatively small wrap of the active or lower run of belt 95 on drive pulley 96 so that only a relatively small drive force can be transmitted to belt 95 from pulley 96 and such drive force does not exceed the frictional resistance to slipping of belt 95 relative to thegcontacted surface of web roll 1b. As arms 99a and 99b continue to move downwardly, the length of belt 95 in driving engagement with the periphery of -roll 1b is progressively increased, thereby correspondingly increasing the distance along belt 95 between drive pulley Y96 and idler pulley 101 and, as a result thereof, take-up pulley 104 is moved progressively toward the right and downwardly, as viewed on FIG. l, against the force of the relatively low pressure of fluid in cylinders 137. Such movement of take-up pulley 104 progressively increases the wrap of belt 95 on drive pulley 96, and thereby progressively increases the driving force transmitted from pulley 96 to belt 95. As the driving force transmitted from pulley 9.6 to accelerating belt 95 is progressively increased, the frictional resistance to relative slipping of belt l95 and web roll 1b is similarly increased by reason of the progressively increasing area of contact therebetween.

The effect of the progressively increasing angle of Wrap the speed of belt 95, and the progressively increasing length of the belt 95 in driving engagement with roll 1b achieves the corresponding acceleration of the web roll without slippage of belt 95 relative thereto. The foregoing action continues until arms 99a and 99!) have reached their fully lowered position shown in full lines on FIG. l, at which time the new web roll 1b has been accelerated up to a peripheral speed matching the speed of movement of the web being unwound from the expiring web roll 1a.

It will be apparent that the flow control valve 151 in providing means for adjusting the rate of downward movement of arms 99a and 99b from the inoperative or raised position thereof, serves to control the rate at which the new web roll is accelerated up to the speed of the web being unwound from the expiring web roll, thereby to adapt the operation of accelerating device 94 for different conditions of roll size and surface characteristics, and for different web speeds.

After the new web roll 1b has been accelerated up to the speed of the web being unwound from the expiring web roll, as described above, and the leading edge of the new web roll is to be spliced to the expiring web, solenoid valve 149 is suitably energized and solenoid valve 155 is simultaneously deenergized, whereby the left-hand end of each cylinder 146 receives fluid under high pressure through conduit 147 from conduit 152, and the right-hand end of cylinder 146 is vented to atmosphere through conduits 148 and 154 and the port 159 of valve 155. The effect of the foregoing is to very substantially increase the contact pressure of belt 95 against the surface of web roll 1b at the moment when the new web is spliced to the expiring web, thereby to ensure the continued non-slip engagement of belt 95 with roll 1b for accurately controlling the rotational speed of the latter, Thus, during acceleration of web roll 1b up to the desired speed, belt 95 is urged against the surface thereof with a relatively small force adequate to avoid any slippage therebetween, thereby to increase the useful life of the accelerating belt, with such contacting force being increased to prevent relative slippage of belt 95 and web roll 1b only momentarily during the actual splicing operation.

In splicing the leading edge of new web roll 1b to the web W unwound from expiring web roll 1a, the latter is pressed, as by a splicing roller 160, against previously applied adhesive on the leading edge portion of the new web roll. Immediately after such splicing has been effected, the web from the expiring web roll is severed at a location a small distance from the splice, as by cutting knives 161. As shown on FIG. l, splicing roller 160 and cutting knives 161 may be mounted, as at 162, on arms 163 extending from a shaft 164 having its ends journaled in side frame members A and B, and the splicing roller and cutting knives may be moved to their operative positions by suitably supplying fluid under pressure to a cylinder 165 having its piston rod 166 connected to an actuating arm 167 alsoV secured on shaft 164. Since the actual splicing operation is not, as such, part of the present invention, the controls for the splicing roller and cutting knives have not been shown or described herein.

Following the splicing of the leading edge portion of the new web roll to the web from the expiring web roll and the severing of the last mentioned web, roll-holding spider arms 11a andv 11b are turned, as described above, to bring new web roll 1b to normal running position R. When the new web roll is in the normal running position, accelerating device 94 is returned to its raised or inoperative position by again deenergizing valve 149 so that the right-hand end of cylinder 146 receives fluid under high pressure through conduits 152 and 148 and the left-hand end of cylinder 146 is vented through conduits 147' and 154 and port 159 of valve 155. The rate of the return movement of accelerating device 94 to its raised or inoperative position is regulated by the adjustable flow control valve 150 in conduit 147.

It will be apparent that, in the automatic splicing rollstand 1t) shown.. as being illustrative of this invention, the drive of new web roll 1b is effectedv in a` manner to avoid any damage thereto during its acceleration, and further in a manner to automatically achieve the necessary matching of the peripheral speed o'f the new web roll t0 the speed of the web being unwound from expiring web roll 1a both before and during the actual splicing or transferring operation, and thereafter to match the speeds at the roll contacting surfaces of belts 46 and 95 for simultaneous driving engagement of such belts with roll 1b in the course of the movement of the new web roll from splicing position S to normal running position R, whereby to avoid excessive disturbance of the web tension during the splicing operation of the rollstand.

y Although an illustrative embodiment of the invention has been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiment, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention, as defined in the appended claims.

What is claimed is:

1. In an apparatus for transferring a running web from a first rotating roll to a second such roll at a moment when the two rolls have substantially different diameters, including a first drive belt having a run thereof in driving engagement with the periphery of said first roll at the moment of transfer, a second drive belt movable from an inoperative position against said second roll so as to engage a progressively increasing length of a run of the second belt with the periphery of said second roll to drive the latter prior to, and at the moment of transfer, and means operative after the transfer to bring said second roll into driving engagement with said first belt by a movement in the course of which the periphery of said .second roll is drivingly engaged by both of said belts:

drive means for said belts including a slippable connection operative in response to movement of said second belt against said second roll to transmit a pro` gressively increasing driving force from said drive means to said second belt as the length of said run of the latter engaging said second roll, and hence the resistance to slipping of said second belt relative to said second roll are progressively increased, whereby to obtain gradual acceleration of said second roll through non-slip engagement thereof by said second belt, and variable drive ratio means providing a .certain drive ratio between said belts at the moment of transfer and providing a different drive ratio therebetween during the simultaneous driving engagement thereof with said second roll, whereby the roll con-I tacting surfaces of both belts are driven at precisely the same speed when individually engaging the first and second rolls, respectively, and when simultaneously engaging the second roll.

2. In a rollstand for delivering a web continuously from one web supply roll after another to a web processing machine, the combination of movable support means for carrying each roll stepwise to successive splicing, running and expiring positions,

a first drive belt having an extended run to engage the periphery of a roll at said running position and at said expiring position, and also to engage the periphery of a roll moving to said running position from said splicing position,

a second drive belt having an extended run and being movable from an inoperative position against a roll at said splicing position to engage a progressively increasing length of said extended run of the second belt with the periphery of the roll at said splicing position, and to maintain driving engagement therewith during movement of the roll from said splicing position toward said running position,

means to drive said iirst and second belts including variable drive ratio means providing a certain drive ratio between said belts when said first and second belts are individually in driving engagement with the peripheries of rolls at said expiring and splicing posi- 17 tions, respectively, and providing a different drive ratio establishing precisely the same speed at the roll contacting surfaces of both belts during the sirnultaneous driving engagement thereof with a roll moving from the splicing position to the running position, and

means providing a slippable connection between said drive means and said second drive belt, and operative in response to movement of the second drive belt from said inoperative position against a roll at the splicing position, to transmit a progressively increasing driving force from said drive means to said second drive belt as the length of the latter engaging a roll at the splicing position, and hence the resistance to slipping of said second belt relative to the roll engaged thereby at the splicing position are progressively increased, whereby to obtain gradual acceleration of the roll through non-slip engagement thereof by said second drive belt.

3. In a rollstand for delivering a web continuously under substantially constant tension from one web supply roll after another to a web processing machine, the combination of movable support means for carrying each roll stepwise to successive splicing, running and expiring positions,

a rst drive belt having an extended run to engage the periphery of a roll at said running position and at said expiring position, and also to engage the periphery of a roll moving to said running position from said splicing position,

a second drive belt having an extended run and being movable from an inoperative position against a roll at said splicing position to engage a progressively increasing length of said extended run of said second belt with the periphery of the roll at said splicing position, and to maintain driving engagement therewith during movement of the roll from said splicing v position toward said running position,

rst variable speed drive means responsive to changes in tension of the web being delivered and having a drive pulley to engage one of said first and second belts and thereby drive said one belt at a variable speed dependent upon the web tension,

second variable speed drive means driven from said first variable speed drive means and having a drive pulley to engage and drive the other of said belts,

control means selectively causing said second variable speed drive means to provide a certain drive ratio v between said belts whensaid first and second belts are respectively in driving engagement with the peripheries of rolls at said expiring and splicing positions, and to provide a different drive ratio establishing the same speed at the roll contacting surfaces of both belts during movement of a roll from the splicing position to the running position, and

means controlling the engagement of said second drive belt with the respective drive pulley, and operative in response to movement of the second drive belt from said inoperative position against a roll at said splicing position to transmit a progressively increasing driving force from the respective drive means to said second drive belt as the length of the latter engaging a roll at the splicing position, and hence the resistance to slipping of said second drive belt relative to the roll engaged thereby at the splicing position are progressively increased, whereby to obtain gradual acceleration of the roll through non-slip engagement by said second drive belt.

4. In an apparatus for transferring a running web from a first rotating roll to a second such roll at a moment when the two rolls have substantially different diameters, including first and second drive belts respectively having runs thereof in individual driving engagement with the peripheries of said first and second rolls at the moment of transfer and means operative after the transfer to bring 18 said second roll into driving engagement with said first belt by a movement in the course of which the periphery of said second roll is drivingly engaged by both of said belts,

drive means -for said belts including variable drive ratio means providing a certain drive ratio between said belts at the moment of transfer and providing a different drive ratio therebetween during the simultaneous driving engagement thereof with said second roll, whereby the roll contacting surfaces of both belts are driven at precisely the same speed when individually engaging said first and second rolls, respectively, and when simultaneously engaging said second roll.

5. In a rollstand for splicing a running web from an expiring web roll of small diameter to the leading edge of a new web roll of relatively large diameter while maintaining a substantially constant web tension, including first and second drive belts respectively having runs thereof in individual driving engagement with the peripheries of said expiring and new web rolls at the moment of splicing and means operative after the splicing to bring said new web roll into driving engagement with said first belt by a movement in the course of which the periphery of said new web roll is drivingly engaged by both of said belts,

drive means for said belts responsive to changes in the tension of the running web to drive said belts at proportioned speeds that vary with web tension, and including variable drive ratio means providing a certain drive ratio between said belts at the moment of splicing and providing a different drive ratio therebetween during the simultaneous driving engagement thereof with said new web roll, whereby the roll contacting surfaces of both belts are driven at precisely the same speed when individually engaging the expiring roll and thel new roll, respectively, and when simultaeously engaging the new roll.

6. In an apparatus for transferring a running web from a first rotating roll to a second such roll ata moment when Vthe two rolls have substantially different diameters, including first and second drive belts respectively having runs thereof in individual driving engagement with the peripheries of said first and second rolls at the moment of transfer and means operative after the transfer to bring said second roll into driving engagement with said first belt by a movement in the course of which the periphery of said second roll is drivingly engaged by lboth of said belts,

drive means for said belts including first and second drive pulleys engaging said irst and second belts, means responsive to changes in the tension of said running web to rotate one ofsaid drive pulleys at a variable speed dependent upon the web tension, variable drive ratio means connecting said first and second drive pulleys, and lcontrol means for said variable drive ratio means causing the latter to provide a certain drive ratio between said belts when the latter are in individual driving engagement with the respective rolls at the moment of transfer and to provide a different drive ratio between the belts during the simultaneous driving engagement thereof with said second roll, wherebythe roll contacting surfaces of both belts are driven at precisely the same speed when individually engaging the respective rolls and when simultaneously engaging said second roll. 7. An apparatus as in claim 6; Y wherein said control means for the variable drive ratio means includes means limiting` the rate of change of the drive ratio between the belts in the course of said movement of the second roll into driving engagement with said first belt. 8. An apparatus as in claim 6; wherein said variable drive ratio means includes a fixed diameter V-belt pulley rotatably coupled to one of said drive pulleys, a variable diameter V-belt pulley rotatably coupled to the other of said drive pulleys, a V-belt running around said fixed and variable diameter V-belt pulleys, a take-up pulley engaging a run of said V-belt between said V-belt pulleys, and a support member rotatably carrying said take-up pulley and being movable between two positions to respectively increase and decrease the effective engaging diameter of said V-belt on said variable diameter pulley; and

wherein said control means includes an actuating device operative to move said support member between said two positions, and dashpot means connected to said support member to control the rate of movement thereof between said two positions and thereby limit the rate of change of the drive ratio between the drive belts in the course of said movement of the second roll into driving engagement with said rst belt.

9. Apparatus for accelerating a web roll, comprising support means rotatably carrying a web roll,

a belt having an extended run to drive said roll and being movable from an inoperative position against said roll so as to engage a progressively increasing length of said extended run with the periphery of said roll, and

drive means for said belt including a slippable connection operative in response to movement of said belt against said roll to transmit a progressively increasing driving force from said drive means to said belt as the length of said run of the belt engaging said roll, and hence the resistance to slipping of the belt relative to the roll are progressively increased, whereby to obtain gradual acceleration of the roll through non-slip engagement thereof by said belt.

10. Apparatus for accelerating a web roll, comprising support means rotatably carrying a web roll,

a frame movable from an inoperative position toward said roll and carrying rotatable drive and idler pulleys,

means rotating said drive pulley,

a belt running around said drive and idler pulleys so as to present an active run which is spaced from said roll in said inoperative position of the frame and which engages a progressively increasing length of said active run with the periphery of said roll and hence increases the resistance to slipping of the belt relative to said roll in response to movement of said frame toward the roll,

a take-up pulley engaging a return run of said belt extending to said drive pulley and being movably mounted on said frame to move in first and second opposed directions for respectively decreasing and increasing the wrap of said belt on said drive pulley, and

means yieldably urging said take-up pulley to move relative to said frame in said first direction for taking up slack in said belt and for decreasing said wrap of the belt on said drive pulley so that, when said frame-is in said inoperative position with said active run of the belt spaced from said roll, there is a minimum wrap of said belt on said drive pulley and, as the frame moves toward said roll and engages a progressively increasing length of said active run of the belt with the roll, said return run acts on said take-up pulley to move the latter in said second direction for progressively increasing the wrap of the belt on the drive pulley and thereby progressively increasing the driving force that can be transmitted from said drive pulley to said belt.

11. Apparatus as in claim further comprising means limiting movement of said take-up pulley in said first direction relative to said frame in said inoperative position of the latter so that slack is present in said belt until said active run of the belt effects initial engagement with said roll. 12. Apparatus as in claim 11; wherein said means limiting movement of the take-up pulley includes a fixed member engageable with said belt on the take-up pulley to hold the belt against movement by the drive pulley.

13. In a rollstand for transferring a running web from an expiring web roll to a new web roll, including first and second drive belts respectively having runs thereof in individual driving engagement with the peripheries of said expiring and new web rolls at the moment of transfer and means operative after the transfer to bring said new web roll into driving engagement with said first belt,

means mounting said second belt for movement from an inoperative position against the new web roll so as to engage a progressively increasing length of said second belt with said new web roll prior to said moment of transfer,

drive means for said second belt including a slippable connection operative in response to movement of said second belt against the new web roll to transmit a progressively increasing driving force from said drive means to said second belt as the length of the latter engaging the new web roll, and hence the resistance to slipping of such belt relative to the new web roll are progressively increased, and

actuating means operative to urge said second belt against the new web roll with a predetermined force sufiicient to ensure non-slip engagement of said second belt with the new web roll during gradual acceleration thereof by the progressively increasing driving force transmitted to said second belt, and to urge said second belt against said new web roll with a substantially increased force during said moment of transfer.

14. In a rollstand for delivering a web continuously from one web supply roll after another, including movable support means for carrying each roll stepwise to successive splicing, running and expiring positions, a continuously driven main drive belt having an extended run to drivingly engage a roll at said running position and at said expiring position, and splicing means operative to join the leading edge of a roll at said splicing position to the web being delivered from a roll at said expiring position,

apparatus for driving a roll at said splicing position and during movement of the roll from said splicing position into driving engagement with said main drive belt at said running position, said apparat-us comprising an accelerating belt having an extended run and being movable from an inoperative position against a roll at said splicing position so as to engage a progressively increasing length of said extended run thereof with the periphery of the roll at the splicing position, means ,selectively operable to move said accelerating belt from said inoperative position against said roll at the splicing position and to return said accelerating belt to said inoperative position, and drive means for said accelerating belt including a drive pulley continuously rotated in synchronism with the movement of said main drive belt and being engageable by said accelerating belt, and means responsive to movement of said accelerating belt against the roll at said splicing position to progressively increase the length of said accelerating belt engaging said driving pulley as the length of said accelerating belt engaging the roll at the splicing position, and hence the resistance to sliding of said accelerating belt relative to the roll are progressively increased, whereby to transmit a progressively increased driving force for effecting gradual acceleration of the roll at the splicing position through nonv slip engagement by said accelerating belt. 415. A rollstand as in claim 14; wherein said means for Ymoving the accelerating belt includes fluid pressure operated actuating means, and means supplying fluid under a predetermined pressure to said actuating means during the gradual acceleration of the roll at the splicing position and increasing the pressure of uid supplied to said actuating means during operation of said splicing means so as to correspondingly increase the contact pressure of said accelerating belt against the roll at said splicing position, whereby to ensure non-slip engagement of the accelerating belt with the roll driven thereby.

16. In a rollstand for delivering a web continuously from one web supply roll after another, including movable support means for carrying each roll stepwise to successive splicing, running and expiring position, a continuously driven main drive belt having an extended run to drivingly engage a roll at said running position and at said expiring position, and splicing means operative to join the leading edge of a roll at said splicing position to the web being delivered from a roll at said expiring position,

apparatus for driving a roll at said splicing position and during movement of the roll from said splicing position into driving engagement with said main drive belt at said running position, said apparatus comprising a drive pulley rotated in synchronism with the movement of said main drive belt, a frame rockable about the axis of said drive pulley from an inoperative position toward a roll at said splicing position and carrying a rotatable idler pulley spaced from said drive pulley, an accelerating belt running around said drive and idler pulleys and presenting an active run therebetween to engage a progressively increasing length of said active run with a roll at said splicing position upon rocking of said frame from said inoperative position, a take-up pulley engaging a return run of said accelerating belt extending to said drive pulley and being movably mounted on said frame to move in iirst and second opposed directions for respectively decreasing and increasing the Wrap of said accelerating belt on said drive pulley, means yieldably urging said take-up pulley in said first direction for taking-up slack in said accelerating belt so that, when said frame is in said inoperative position, said active run is spaced from a roll at said splicing position and said accelerating belt has a minimum wrap on said drive pulley, and means for rocking said frame from said inoperative position toward a roll at said splicing position so that, in response to the progressively increasing length of said active run engaging the roll, and hence a progressive increase in the resistance to slipping of said accelerating belt relative to the roll engaged thereby, said return run acts on the take-up pulley to move the latter in said second direction for progressively increasing said wrap of the accelerating belt on said drive pulley, whereby to progressively increase the force that can be transmitted from said drive pulley to said accelerating belt for non-slip application by said increasing length of said active run to the roll at said splicing position.

17. A rollstand as in claim 16;

wherein said means for rocking said frame includes fluid pressure operated actuating means, means for supplying fluid at a irst pressure to said actuating means during said rocking of the frame from said inoperative position so that the contact force of said active run on a roll at the splicing position is adequate to prevent relative slipping therebetween as the transmitted driving force is progressively increased, and means for supplying fluid at an increased pressure to saidactuating means during operation of said splicing means so as to then provide a correspondingly increased contact force of said accelerating belt against a roll at the splicing position.

References Cited UNITED STATES PATENTS `2,344,952 3/ 1944 Wieking 242-75.42 2,365,528 12/ 1944 Dietrich 242--58.3 3,23 6,470 2/ 1966 Huck 242-583 LEONARD D. CHRISTIAN, Primary Examiner. 

1. IN AN APPARATUS FOR TRANSFERRING A RUNNING WEB FROM A FIRST ROTATING ROLL TO A SECOND SUCH ROLL AT A MOMENT WHEN THE TWO ROLLS HAVE SUBSTANTIALLY DIFFERENT DIAMETERS, INCLUDING A FIRST DRIVE BELT HAVING A RUN THEREOF IN DRIVING ENGAGEMENT WITH THE PERIPHERY OF SAID FIRST ROLL AT THE MOMENT OF TRANSFER, A SECOND DRIVE BELT MOVABLE FROM AN INOPERATIVE POSITION AGAINST SAID SECOND ROLL SO AS TO ENGAGE A PROGRESSIVELY INCREASING LENGTH OF A RUN OF THE SECOND BELT WITH THE PERIPHERY OF SAID SECOND ROLL TO DRIVE THE LATTER PRIOR TO, AND AT THE MOMENT OF TRANSFER, AND MEANS OPERATIVE AFTER THE TRANSFER TO BRING SAID SECOND ROLL INTO DRIVING ENGAGEMENT WITH SAID FIRST BELT BY A MOVEMENT IN THE COURSE OF WHICH THE PERIPHERY OF SAID SECOND ROLL IS DRIVINGLY ENGAGED BY BOTH OF SAID BELTS: DRIVE MEANS FOR SAID BELTS INCLUDING A SLIPPABLE CONNECTION OPERATIVE IN RESPONSE TO MOVEMENT OF SAID SECOND BELT AGAINST SAID SECOND ROLL TO TRANSMIT A PROGRESSIVELY INCREASING DRIVING FORCE FROM SAID DRIVE MEANS TO SAID SECOND BELT AS THE LENGTH OF SAID RUN OF THE LATTER ENGAGING SAID SECOND ROLL, AND HENCE THE RESISTANCE TO SLIPPING OF SAID SECOND BELT RELATIVE TO SAID SECOND ROLL ARE PROGRESSIVELY INCREASED, WHEREBY TO OBTAIN GRADUAL ACCELERATION OF SAID SECOND ROLL THROUGH NON-SLIP ENGAGEMENT THEREOF BY SAID SECOND BELT, AND VARIABLE DRIVE RATIO MEANS PROVIDING A CERTAIN DRIVE RATIO BETWEEN SAID BELTS AT THE MOMENT OF TRANSFER AND PROVIDING A DIFFERENT DRIVE RATIO THEREBETWEEN DURING THE SIMULTANEOUS DRIVING ENGAGEMENT THEREOF WITH SAID SECOND ROLL, WHEREBY THE ROLL CONTACTING SURFACES OF BOTH BELTS ARE DRIVEN AT PRECISELY THE SAME SPEED WHEN INDIVIDUALLY ENGAGING THE FIRST AND SECOND ROLLS, RESPECTIVELY, AND WHEN SIMULTANEOUSLY ENGAGING THE SECOND ROLL. 